Classify real numbers i can possibly help with! hmu! ill help
45 or a random number lol just put in 45 and see if it orks
The confidence interval would be
![0.80\pm0.03](https://tex.z-dn.net/?f=0.80%5Cpm0.03)
.
We use the formula
![p\pm z*\sigma_p](https://tex.z-dn.net/?f=p%5Cpm%20z%2A%5Csigma_p)
, where
![\sigma_p=\sqrt{\frac{p(1-p)}{N}}](https://tex.z-dn.net/?f=%5Csigma_p%3D%5Csqrt%7B%5Cfrac%7Bp%281-p%29%7D%7BN%7D%7D)
, with p being the sample proportion and N being the sample size.
First we find the z-score associated with this level of confidence:
Convert 95% to a decimal: 95/100 = 0.95
Subtract from 1: 1-0.95 = 0.05
Divide by 2: 0.05/2 = 0.025
Subtract from 1: 1-0.025 = 0.975
Using a z-table (http://www.z-table.com) we see that this value is associated with a z-score of 1.96.
Since 578/720 said yes, this gives us p=0.80:
![\sigma_p=\sqrt{\frac{0.80(1-0.80)}{720}}=\sqrt{\frac{0.8(0.2)}{720}=0.015](https://tex.z-dn.net/?f=%5Csigma_p%3D%5Csqrt%7B%5Cfrac%7B0.80%281-0.80%29%7D%7B720%7D%7D%3D%5Csqrt%7B%5Cfrac%7B0.8%280.2%29%7D%7B720%7D%3D0.015)
This gives us
1/10 is the probability.
You find this by putting 25/250 and simplifying.